1. Field of the Invention
The present invention generally relates to a chip thermal dissipation structure, and more particularly to a chip thermal dissipation structure employed in an electronic device comprising one or more chips.
2. Description of Prior Art
The development of integrated circuit technology nowadays has become unprecedented and innovative. The size of the chips becomes smaller and smaller. The design of the electronic device, such as digital cameras, mobile phones, phablets and other various kinds of electronic devices continue to be microminiaturized. The amount of the integrated circuit components, such as chips utilized in those electronic devices is not merely few. In such highly competitive capital market, the efficiency electronic devices are doomed to be constantly raised for obtaining the advantages of product competitions. Therefore, the chips, the integrated circuit components, such as microprocessors, communication chips with various specifications, memories, audio/video processing chips and etc. The working frequencies are constantly competing to increase. As increasing the working frequencies for obtaining the advantages of product competitions, the designs of the electronic devices are required to be light, and thin, and small. However, the working frequencies of the chips and the integrated circuit components which are considered as heat sources are required to be raised. The amounts of the chips and the integrated circuit components are increasing and the heat densities inevitably increase. Consequently, the heat densities inside the electronic devices are constantly raised higher and higher.
However, for the aforesaid electronic devices, silence is essential requirement and feature. A general active heat dissipation means, such as a fan is impossibly suitable for the electronic devices which are required to be light, thin and small. The heat sink efficiency of a passive heat dissipation means cannot compete with the active heat dissipation means but demands for being light, thin and small can be realized thereby. The passive heat dissipation is definitely the chosen skill for the electronic devices which are required to be light and thin and small.
However, the challenge that the heat dissipation of the electronic devices faces becomes more and more severe.
Please refer to FIG. 1, which depicts a structure diagram of an electronic device having a chip A according to prior arts. As the arrangement shown in FIG. 1, a chip of a general electronic device is commonly located inside the electronic device. The structure of the electronic device comprises an upper shell 1, chip molding material 2, a plurality of bumps 3, a packaging substrate 4, a plurality of solders 5, a printed circuit board 6 and a lower shell 7. After the chip A is packaged by the packaging substrate 4 with the bumps 3, the chip molding material 2 is utilized for covering the chip A. The packaging substrate 4 connects with the printed circuit board 6 via solders 5. The printed circuit board 6 is fixed at the lower shell 7 with several fixing screws.
As shown in FIG. 1, a certain space between the chip molding material 2 and the upper shell 1 should be reserved; another certain space also should be reserved between the printed circuit board 6 and the lower shell 7. Sometimes, underfill material, such as epoxy is filled among the plurality of bumps 3. Because the thermal conductivity coefficient of the air is very low, therefore, the upward path of the heat flow thermal conductivity is stopped at the chip molding material 2 when the chip A generates heat. Many elements, such as the underfill material filled among the bumps 3 which has bad thermal conductivity, the dielectric layer material in the packaging substrate 4, the dielectric layer material in the print circuit board 6 and etc exist in the downward path of the heat flow thermal conductivity, the conductivity of the thermal energy generated by the Chip A is interfered thereby.
Accordingly, the heat density in unit volume must constantly accumulate with the working time of the chip A. Moreover, for realizing the light, thin and small requirements for the designs of the electronic devices, multiple chip integrated package has already become a main trend for now. When the chip A and other chips with lower temperatures are packaged in integration and the old heat dissipation design is utilized in the electronic devices, the heat flow path of the thermal energy generated by the chip A is inevitably conducted toward other chips (The thermal conductivity of the heat flow naturally tends toward the directions of lower thermal conductivity coefficient) and affect the other chips. Consequently, the structure temperature of the whole electronic device must be raised. The performance is affected. The power consumption is increased. Moreover, the lifetime of the electronic device is shortening even more.